1. Field of the Invention
The present invention relates to occlusal force measuring apparatus.
2. Related Background Art
The conventionally known apparatus for measuring the occlusal force being the bite force of the upper and lower teeth includes such a system that a pressure sensitive sheet is inserted into the oral cavity to be bitten and that occlusal traces recorded in the pressure sensitive sheet are read by a scanner to gain the occlusal force, and such a system that a compact pressure detector filled with liquid is inserted into the oral cavity to be bitten and that a pressure transmitted through the liquid is measured by a load cell located outside.
However, since the measuring system with the pressure sensitive sheet is configured to insert the pressure sensitive sheet into the oral cavity to make it bitten and thereafter analyze the pressure sensitive sheet in a post-step, it does not allow real-time measurement and can measure only the maximum occlusal force during occlusion. In the case of the measuring system with the compact pressure detector, this detector has to be bitten in the oral cavity and thus the system cannot measure the occlusal force in a natural state as if to chew food.
The present invention has been accomplished in view of the above problems and an object of the invention is to provide occlusal force measuring apparatus that can measure the occlusal force in real time without the necessity for biting any detector or the like at all.
An occlusal force measuring apparatus according to the present invention is an apparatus for measuring an occlusal force of a subject, which comprises a light irradiating section for irradiating a muscle used for occlusion of teeth of the subject, with light; a light detecting section for detecting scattered light from the muscle upon irradiation of the muscle with the light; an oxygen saturation acquiring section for acquiring an oxygen saturation, based on the scattered light; a correlation data storing section prestoring correlation data between oxygen saturation and occlusal force; and an occlusal force calculating section for calculating an occlusal force corresponding to the oxygen saturation acquired by the oxygen saturation acquiring section, based on the correlation data stored in the correlation data storing section.
According to the present invention, the light irradiating section irradiates the muscle used for the occlusion of teeth, with the light and the light detecting section detects the scattered light from the muscle; thus, the oxygen saturation of this muscle is acquired based on the scattered light. Further, the occlusal force of the subject is calculated based on the correlation between oxygen saturation and occlusal force.
In a preferred embodiment, a set of a light irradiating section and a light detecting section constitute a left scattered light acquiring section mountable on the left side of the subject""s face, and another set of a light irradiating section and a light detecting section constitute a right scattered light acquiring section mountable on the right side of the subject""s face. This configuration permits the apparatus to calculate left and right occlusal forces of the subject independently of each other.
The apparatus may be configured to comprise a left and right comparing section for comparing left and right occlusal forces calculated based on scattered light detected by the left scattered light acquiring section and the right scattered light acquiring section. This configuration permits the apparatus to compare the left and right occlusal forces of the subject with each other.
The apparatus may also be configured so that the correlation data storing section stores correlation data between oxygen saturation and occlusal force for every subject and the occlusal force calculating section calculates the occlusal force, based on the correlation data for every subject. In this configuration, the occlusal force calculating section calculates the occlusal force, based on the correlation data between oxygen saturation and occlusal force for every subject.
The apparatus may also be configured to comprise a reference occlusal force storing section storing a reference occlusal force and a clenching situation acquiring section for acquiring the number of times that the calculated occlusal force becomes not less than the reference occlusal force, hours when the calculated occlusal force becomes not less than the reference occlusal force, and occlusal forces at the hours. This configuration permits the apparatus to acquire clenching situations of the subject with variation in time.
The apparatus may also be configured to comprise a reference occlusal force storing section storing a reference occlusal force and a ratio calculating section for calculating a ratio of the calculated occlusal force to the reference occlusal force. This configuration permits the apparatus to calculate the ratio of the current occlusal force to the reference occlusal force.
The apparatus may also be configured to comprise a standard mastication storing section storing a time variation of occlusal force during chewing of a predetermined food, and a mastication comparing section for comparing the time variation of occlusal force during the chewing of the predetermined food with a time variation of the calculated occlusal force. This configuration permits the apparatus to compare the time variation of occlusal force during the subject""s mastication of the food with standard values.
The apparatus may also be configured to comprise an individual occlusal force storing section storing the calculated occlusal force for every subject, and an occlusal force comparing section for comparing the calculated occlusal force with the occlusal force of each subject stored. This configuration permits the apparatus to compare the current occlusal force of the subject with the occlusal force measured in the past.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.